This invention relates to an improvement of an entrained bed coal gasifier.
There are various types of coal gasifiers such as fixed bed, fluidized-bed, entrained bed, and the like, these being under development. The gasifiers are required to have various performance such as (a) the gasification efficiency is high; (b) the operational control is easy, (c) no pollutive substance is produced, (d) coal throughput capacity per one gasifier is large, (e) various types and ranks of coal can be treated, and (f) the reliability is high and the life is long. The entrained bed gasifier is highly expected to satisfy totally the above-mentioned requirements compared with other types of gasifiers.
According to an entrained bed coal gasification process, pulverized coal usually having a particle size of 100 .mu.m or less is fed through a burner to a gasifier, wherein the coal is reacted at a melting point of coal ash or higher by a gasifying agent (e.g. oxygen, air, steam, and the like). As a result, gases rich in hydrogen and carbon monoxide can be obtained by the following reactions: EQU Coal.fwdarw.Char (C, H)+H.sub.2 +CO+CH.sub.4 ( 1) EQU C+O.sub.2 .fwdarw.CO.sub.2 ( 2) EQU C+1/2O.sub.2 .fwdarw.CO (3) EQU H.sub.2 +1/2O.sub.2 .fwdarw.H.sub.2 O (4) EQU CH.sub.4 +1/2O.sub.2 .fwdarw.2H.sub.2 +CO (5) EQU C+CO.sub.2 .fwdarw.2CO (6) EQU C+H.sub.2 O.fwdarw.CO+H.sub.2 ( 7)
In order to meet the above-mentioned requirements (a) through (f), there are various types of entrained bed gasifiers, which can be classified as mentioned below from the viewpoints of (I) reaction types, (II) burner arrangement, and (III) whole gasifier structures.